# module Parsistence
#   class Relation
#     attr_accessor :PFRelation, :belongs_to, :klass
    
#     def initialize(pf_relation)
#       self.PFRelation = pf_relation

#     end

#     def fetch(&block)
#       if self.belongs_to
#         self.PFRelation.fetchIfNeededInBackgroundWithBlock do |result, error|
#           if result
#             result = self.klass.new(result)
#           end

#           block.call(result, error)
#         end
#       else
#         self.PFRelation.
#       end
#     end

#     def fetchAll(&block)
#       self.fetch(block)
#     end
#   end
# end